The present invention relates to a hose of elastomeric material having an insert of metal material for making the hose diffusion-proof. Hoses of this type are disclosed in e.g. U.S. Pat. Nos. 3,175,586 and 4,559,973. These hoses have inner and outer layers of elastomeric material which are sometimes reinforced. Between these inner and outer layers, a helically wound metal foil layer is disposed in such a manner that a slight overlap is obtained between adjoining convolutions of the metal foil strip. These prior-art hoses have been extensively used in cases where diffusion proofness is required. The known hoses are elastic and have a certain degree of resilience, which may be desirable in many cases. However, when these hoses are subjected to heavy bending, there is an obvious risk that the different metal foil layers may be pulled away from each other at the slightly overlapping joints.
In many applications, e.g. in the car industry, there is a widespread need of hoses having a stable, curved shape, sometimes with several bends of different orientation. In such cases, conventional hoses have hitherto been replaced by a plastically deformable metal tube, or the hose has been built on a mandrel having the desired geometry of curvature. Both these approaches are disadvantageous in different ways.